Nuprl Lemma : decidable__dstype_equal
∀[A:Type]. ∀a:A. ∀d:DS(A). ∀x,y:dstype(A; d; a).  Dec(x = y ∈ dstype(A; d; a))
Proof
Definitions occuring in Statement : 
dstype: dstype(TypeNames; d; a)
, 
discrete_struct: DS(A)
, 
decidable: Dec(P)
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
dstype: dstype(TypeNames; d; a)
, 
discrete_struct: DS(A)
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
pi1: fst(t)
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
Lemmas referenced : 
deq_wf, 
decidable-equal-deq, 
equal_wf, 
pi1_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
lambdaFormation, 
productElimination, 
thin, 
sqequalHypSubstitution, 
cut, 
applyEquality, 
functionExtensionality, 
hypothesisEquality, 
cumulativity, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesis, 
independent_functionElimination, 
dependent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
instantiate, 
functionEquality, 
universeEquality, 
lambdaEquality, 
dependent_pairEquality, 
productEquality
Latex:
\mforall{}[A:Type].  \mforall{}a:A.  \mforall{}d:DS(A).  \mforall{}x,y:dstype(A;  d;  a).    Dec(x  =  y)
Date html generated:
2017_04_17-AM-09_09_46
Last ObjectModification:
2017_02_27-PM-05_17_49
Theory : decidable!equality
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